Transmission mechanism of electric control power assisting device

Abstract

The utility model discloses a transmission mechanism of an electric control power assisting device, which comprises a lead screw nut, a lead screw and a speed reducing device, the speed reducing device comprises a primary gear and a secondary gear, a connecting shaft is arranged in the electric control power assisting device, the primary gear is sleeved on the connecting shaft, a small gear is fixedly connected on a motor output shaft of the electric control power assisting device, and the small gear is sleeved on the secondary gear. The pinion is meshed with the first-stage gear, the first-stage gear is meshed with the second-stage gear, a first step shaft is arranged on the outer wall of the lead screw nut, the second-stage gear is arranged on the first step shaft in a sleeving mode, the second-stage gear is fixedly connected with the first step shaft through a flat key, a lead screw is in transmission connection in the lead screw nut, and a supporting structure is further arranged on the lead screw nut. The supporting structure is in interference fit with the lead screw nut, the motor output shaft amplifies torque through the speed reducer and then drives the lead screw nut to rotate, rotary motion is converted into linear motion of the lead screw, the lead screw is made to move in the axial direction, the first-stage gear and the second-stage gear achieve step-by-step amplification of the torque, and the transmission ratio and the output force are improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of automobile braking, in particular to a transmission mechanism of electric control booster device. BACKGROUND

[0002] The brake pedal is an extremely important component inside the automobile, and its use frequency is self-evident, almost all driving braking related operation inputs are directly or indirectly realized through this component. Whether it is deceleration parking in daily driving or emergency brake, the brake pedal plays a crucial role. In order to improve the convenience and safety of driving, modern cars are generally equipped with brake booster and other auxiliary equipment, and the core goal of these equipment is to provide a more relaxed and efficient brake experience for the driver.

[0003] The electric control booster is a key component in the brake booster system, and its working principle is that when the driver steps on the brake pedal, the input rod generates displacement, the system calculates the torque that the motor should provide according to the displacement, and then the transmission mechanism converts the torque into servo braking force to establish hydraulic pressure in the brake master cylinder, and finally realize braking. In the existing electric control booster device, the transmission mechanism adopts single-stage gear reduction structure, and the brake force is transmitted through the motor driving screw. However, the transmission ratio of single-stage gear reduction is limited, resulting in small output force, which is difficult to meet the demand of heavy vehicles such as light trucks for larger braking force, so it is necessary to improve. UTILITY MODEL CONTENTS

[0004] The utility model aims at the defects and deficiencies of prior art, and provides a transmission mechanism of electric control booster device, which is simple and reasonable in structure and convenient to operate, and can realize two-stage speed reduction effect through the design of primary gear and secondary gear, realize step-by-step amplification of torque, and further significantly improve the transmission ratio and output force.

[0005] In order to achieve the above purpose, the utility model adopts the following technical scheme:

[0006] The utility model relates to a transmission mechanism of electric control power assisting device, including screw nut, screw rod and reduction gear, the reduction gear includes primary gear and secondary gear, be provided with the connecting shaft that matches with primary gear in electric control power assisting device, primary gear is sleeved on the connecting shaft, the motor output shaft of electric control power assisting device is fixedly connected with pinion, pinion engages with primary gear, primary gear engages with secondary gear, first step shaft is set up on the outer wall of screw nut, secondary gear is sleeved on first step shaft, and secondary gear and first step shaft are fixedly connected through the flat key, screw rod is drivenly connected in screw nut, still be provided with support structure on screw nut for supporting the rotation of screw nut, the support structure is interference fit with screw nut, the motor output shaft drives screw nut to rotate after the amplification of torque through reduction gear, thereby converts the linear motion of screw rod into the rotary motion, makes screw rod move along the axial direction.

[0007] Further, the support structure includes a first bearing and a second bearing, the first bearing and the second bearing are respectively sleeved on both ends of the screw nut, the inner ring of the first bearing and the inner ring of the second bearing are both radially interference fit with the screw nut.

[0008] Further, a second step shaft corresponding to the first bearing is arranged on the screw nut, and the first bearing is sleeved on the second step shaft.

[0009] Further, a limiting washer is arranged between the secondary gear and the second bearing, and the secondary gear is limitedly fit with the second bearing through the limiting washer.

[0010] Further, the screw rod is of a hollow structure.

[0011] Further, a third bearing and a fourth bearing corresponding to the primary gear are sleeved on the connecting shaft, the third bearing and the fourth bearing are respectively arranged at both ends of the primary gear, and the inner ring of the third bearing and the inner ring of the fourth bearing are both radially interference fit with the connecting shaft.

[0012] Further, the outer ring of the third bearing and the outer ring of the fourth bearing are both interference fit with the primary gear.

[0013] Further, a plurality of balls are arranged between the screw rod and the screw nut, and the screw nut is drivingly connected with the screw rod through the balls.

[0014] The utility model has the advantages that compared with the conventional single-stage gear transmission, the transmission mechanism of the electric control power assisting device can realize the secondary reduction effect through the design of the primary gear and the secondary gear, realize the step-by-step amplification of the torque, and significantly improve the transmission ratio and the output force.

[0015] The supporting structure is in interference fit with the screw nut, ensures stable and reliable connection, the motor output shaft drives the screw nut to rotate after amplifying the torque through the primary gear and the secondary gear, thereby converting the rotary motion into the linear motion of the screw rod, and moving the screw rod in the axial direction. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a sectional structure schematic view of the utility model;

[0017] Figure 2 is Figure 1 the enlarged structure schematic view of A in the figure.

[0018] Figures 1-2 1, screw nut; 11, first stepped shaft; 111, flat key; 12, second stepped shaft; 2, screw rod; 3, speed reducer; 31, primary gear; 311, connecting shaft; 312, third bearing; 313, fourth bearing; 32, secondary gear; 4, pinion; 5, supporting structure; 51, first bearing; 52, second bearing; 6, limiting washer. DETAILED DESCRIPTION

[0019] The utility model will be further described below in combination with the drawings.

[0020] As Figures 1-2 shown in a kind of electric control power-assisted device's transmission mechanism, including screw nut 1, screw rod 2 and speed reducer 3, the speed reducer 3 includes primary gear 31 and secondary gear 32, the electric control power-assisted device is provided with connecting shaft 311 with primary gear 31 cooperation, the primary gear 31 is sleeved on connecting shaft 311, the motor output shaft of the electric control power-assisted device is fixedly connected with pinion 4, the pinion 4 is engaged with primary gear 31, the primary gear 31 is engaged with secondary gear 32, further power transmission, the outer wall of screw nut 1 is provided with first stepped shaft 11, the secondary gear 32 is sleeved on first stepped shaft 11, can effectively position secondary gear 32, prevent its axial or radial movement, refer to Figure 2, the second step shaft 12 and the first bearing 51 correspondingly match, the first bearing 51 is sleeved on the second step shaft 12, can effectively position the first bearing 51, prevent its axial or radial movement.

[0021] Specifically, referring to Figure 1 , the motor output shaft of the electric control power assisting device rotates, drives the pinion 4 to rotate synchronously, the pinion 4 drives the primary gear 31 to rotate, the rotation of the primary gear 31 drives the rotation of the secondary gear 32, the secondary gear 32 is fixedly connected with the lead screw nut 1 through the key 111, the stable transmission of power is ensured, the lead screw nut 1 rotates and is drivingly connected with the lead screw 2 through the ball, thereby converting the rotary motion into the linear motion of the lead screw 2, and driving the lead screw 2 to move in the axial direction.

[0022] Preferably, in the embodiment, referring to Figure 1 , the support structure 5 includes the first bearing 51 and the second bearing 52, the first bearing 51 and the second bearing 52 are respectively sleeved on the two ends of the lead screw nut 1, the inner ring of the first bearing 51 and the inner ring of the second bearing 52 are in radial interference fit with the lead screw nut 1, the close combination between the first bearing 51, the second bearing 52 and the lead screw nut 1 is ensured, thereby effectively improving the rigidity and the carrying capacity of the entire support structure 5.

[0023] Preferably, in the embodiment, the lead screw nut 1 is provided with the second step shaft 12 corresponding to the first bearing 51, the first bearing 51 is sleeved on the second step shaft 12, can effectively position the first bearing 51, prevent its axial or radial movement.

[0024] Preferably, in the embodiment, referring to Figure 2 , the secondary gear 32 and the second bearing 52 are further provided with the limiting washer 6, the secondary gear 32 is limitingly matched with the second bearing 52 through the limiting washer 6, can effectively play the limiting role.

[0025] Preferably, in the embodiment, referring to Figure 1 , the connecting shaft 311 is sleeved with a third bearing 312 and a fourth bearing 313 matched with the primary gear 31, the third bearing 312 and the fourth bearing 313 are respectively arranged at two ends of the primary gear 31, and the inner ring of the third bearing 312 and the inner ring of the fourth bearing 313 are both in radial interference fit with the connecting shaft 311. The tight combination between the first bearing 51 and the second bearing 52 and the lead screw nut 1 is ensured, so as to effectively improve the rigidity and carrying capacity of the whole support structure 5.

[0026] Preferably, in the embodiment, the outer ring of the third bearing 312 and the outer ring of the fourth bearing 313 are both in interference fit with the primary gear 31, so as to ensure the stability and reliability of the connection.

[0027] The above only describes the preferred embodiment of the utility model, so equivalent changes or modifications made according to the structure, features and principles described in the utility model patent application range are included in the utility model patent application range.

Claims

1. A transmission mechanism of an electrically controlled power assisting device, comprising a screw nut (1), a screw rod (2) and a speed reducing device (3), characterized in that: The speed reducer (3) comprises a primary gear (31) and a secondary gear (32), a connecting shaft (311) matched with the primary gear (31) is arranged in the electric control assisting device, the primary gear (31) is sleeved on the connecting shaft (311), a pinion (4) is fixedly connected on a motor output shaft of the electric control assisting device, the pinion (4) is engaged with the primary gear (31), the primary gear (31) is engaged with the secondary gear (32), a first stepped shaft (11) is arranged on an outer wall of the lead screw nut (1), the secondary gear (32) is sleeved on the first stepped shaft (11), and the secondary gear (32) and the first stepped shaft (11) are fixedly connected through a flat key (111); the lead screw nut (1) is drivingly connected with a lead screw (2), the lead screw nut (1) is further provided with a supporting structure (5) for supporting the rotation of the lead screw nut (1), the supporting structure (5) is in interference fit with the lead screw nut (1), the motor output shaft drives the lead screw nut (1) to rotate after amplifying the torque through the speed reducer (3), so as to convert the rotary motion into the linear motion of the lead screw (2) and make the lead screw (2) move in the axial direction.

2. An electric power steering apparatus transmission mechanism according to claim 1, characterized by: The supporting structure (5) comprises a first bearing (51) and a second bearing (52), the first bearing (51) and the second bearing (52) are respectively sleeved on two ends of the lead screw nut (1), and the inner rings of the first bearing (51) and the second bearing (52) are in radial interference fit with the lead screw nut (1).

3. An electrically controlled power assisting apparatus transmission mechanism according to claim 2, characterized by: A second stepped shaft (12) corresponding to the first bearing (51) is arranged on the lead screw nut (1), and the first bearing (51) is sleeved on the second stepped shaft (12).

4. An electrically controlled power assisting apparatus transmission mechanism according to claim 2, characterized by: A limiting washer (6) is further arranged between the secondary gear (32) and the second bearing (52), and the secondary gear (32) is limitedly matched with the second bearing (52) through the limiting washer (6).

5. The transmission mechanism of an electrically controlled power assist device according to claim 1, characterized by: The lead screw (2) has a hollow structure.

6. An electric power steering apparatus transmission mechanism according to claim 1, characterized by: Third and fourth bearings (312 and 313) matched with the primary gear (31) are sleeved on the connecting shaft (311), the third and fourth bearings (312 and 313) are respectively arranged at two ends of the primary gear (31), and the inner rings of the third and fourth bearings (312 and 313) are in radial interference fit with the connecting shaft (311).

7. An electrically controlled power assist device transmission mechanism according to claim 6, characterized in that: The outer rings of the third and fourth bearings (312 and 313) are in interference fit with the primary gear (31).

8. The transmission mechanism of an electrically controlled power assist device according to claim 1, characterized by: A plurality of balls are arranged between the lead screw (2) and the lead screw nut (1), and the lead screw nut (1) is drivingly connected with the lead screw (2) through the balls.

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